The ageless wonder
The illness to McGrath's wife Jane prevented him from going to South Africa and Bangladesh and there were serious concerns about whether he could re-find his immaculate rhythm on a diet of one-day matches in Malaysia and India. A definitive verdict is a couple of lengthy spells away, but his re-entry was stunning and England are suffering.
McGrath, 36, was bowling quicker than at any time during the Champions Trophy - he was in the low 130s - and the Gabba bounce added to his allure. He said it felt like Christmas. Not for England.
"To get a couple of wickets early on does wonders for the confidence," he said. "I'm almost exactly where I can be and am really looking forward to day three. I reckon I can really nail it."
Andrew Strauss provided McGrath with his first victim by top-edging a pull to Michael Hussey, who ran into Brett Lee as he sprinted behind square leg. Lee suffered a cut from Hussey's spikes - "it was a bit of a scratch, I wouldn't have gone off," McGrath smiled - and went for treatment as McGrath dished out more of his own.
He had seen Alastair Cook during the warm-up match for New South Wales and devised his plan to target him from around the wicket. It is becoming the standard way to attack left-handers after Hussey and Adam Gilchrist fell to the same tactic today.
"A couple of balls before, Cook smoked one through the covers and was able to free his arms," he said. "I was trying to get it a fraction fuller and straighter and it really flew off the edge."
Angling in, the ball straightened and Shane Warne took a smart catch at first slip. Paul Collingwood avoided being part of a hat-trick and McGrath finished with 2 for 25 from six overs.
The cracks in the pitch are already widening and McGrath expects the next three days to be more difficult for batting. England trail by 549 runs and McGrath said Australia wanted to "drive it home". "We don't want to take it too easy," he said. "We want to get out there and nail it and show why we are the best team in the world."
McGrath has an almost photographic memory when it comes to his bowling dismissals and he offered a timely warning to those already calling the series as dead. "We've got a lot of momentum and the confidence is with us," he said. "You only have to look at the first Test at Lord's [in 2005] where we won the Test quite convincingly and England came back."
Peter English is the Australasian editor of Cricinfo